He didn’t shove anyone this time, but President Donald Trump’s body language during NATO events Wednesday suggested his relationships with key U.S. allies aren’t exactly buddy-buddy.

Trump started the day with a tense breakfast meeting with Jens Stoltenberg in which he lectured the NATO leader about member defense spending and complained about a German pipeline deal with Russia. Arms crossed over his chest, Trump gestured at Stoltenberg and repeatedly interrupted the secretary-general as he argued his case.

Their subsequent encounters at NATO headquarters were formal and less strained as they twice shook hands and chatted in front of journalists. But those moments were more perfunctory than Stoltenberg’s chattier introductions with other leaders, many of whom Stoltenberg was seeing for the first time that day after he had spent part of the morning hosting Trump.

World leader summits are largely about optics and presenting a united front to the rest of the world. But Trump barreled into his second NATO summit, as he did his first, with a litany of public complaints about alliance members’ “delinquent” defense spending, as well as a German-Russian gas pipeline deal.

Showing unity seemed an afterthought for the “America First” president. And it showed.

During moments that were visible to the press, Trump often separated himself from most of his counterparts, particularly those with whom he has had public disagreements, such as British Prime Minister Theresa May, German Chancellor Angela Merkel and Canada’s Justin Trudeau.

When the leaders strolled out of the gleaming NATO building in Brussels for the traditional family photo in the courtyard, Trump lingered behind and mostly spoke with Turkish President Recep Tayyip Erdogan and Croatian President Kolinda Grabar-Kitarovic.

WATCH: NATO leaders pose for traditional group photo as summit begins

On the dais, he and May chatted as they stood together, but Trump kept his back toward other leaders, including Merkel.

After the group moved inside for talks, Trump again hung back as other heads of state glad-handed around the room. He stayed close to members of his delegation, including Defense Secretary Jim Mattis and Secretary of State Mike Pompeo, before eventually engaging in a brief round of backslapping with others, including again May, before taking his seat.

Trump has harshly criticized May, Merkel and Trudeau since taking office and opened Wednesday with another broadside against Merkel, asserting that her country is “totally controlled” and “captive” to Russia as he objected to a deal to bring Russian natural gas directly to Germany.

Merkel pushed back, insisting that Germany makes its own decisions. When the two met later Wednesday, Trump told reporters: “We have a very, very good relationship with the chancellor.” The comment illustrated how Trump often seeks to avoid conflict with people when he is face to face with them versus the often-harsher rhetoric he uses when he’s talking behind their back. Merkel was not present at Trump’s breakfast with Stoltenberg.

When it was her turn to address reporters in the room for the meeting with Trump, Merkel made no similar declaration about her relationship with Trump.

The two barely looked at each other during the few minutes journalists were allowed in the room. That was in stark contrast to Trump’s subsequent meeting with French President Emmanuel Macron. The Frenchman is one of Trump’s closest friends on the world stage despite their many areas of disagreement, including Trump’s decision to pull out of the Iran nuclear agreement and the Paris climate accord, and to impose tariffs on France and other European countries.

Trump and Macron bantered easily during their joint photo op, with Trump calling it “an honor to be with a friend of mine.” The two also chatted each other up as Macron walked Trump out of the NATO building at the end of the day.

By evening, arriving at a dinner hosted by the Belgian government at the Art and History Museum at the Cinquantenaire, Trump appeared to be in a more social mood. The president, who doesn’t drink alcohol, huddled during the cocktail reception with Stoltenberg for several minutes, before being joined by Merkel for an animated discussion. As Trump spoke again with Erdogan, his wife, Melania, was greeted warmly by Trudeau.

At last year’s NATO summit, tongues wagged after Trump appeared to shove Prime Minister Dusko Markovic of Montenegro to get to the front of the group as leaders entered the alliance’s new headquarters building. Markovic later characterized the incident as “a completely harmless event.”